For his part, Darwin noted in On the Origin of Species that a bear swimming with its mouth agape to catch insects was a plausible evolutionary starting point for whales.

• 达尔文在《物种原始论》第一版中说道，在美洲有人观察到黑熊一面在水中游泳，一面张大嘴巴捕捉昆虫，我们可以合理地推测那是鲸豚类的演化起点。